As I've already said to the OP over some PM's we had about this watch, the movement will need a lot of parts replaced. Rust is not just something that forms on the surface of parts, but in forming it eats away material. Removing the rust, in particular rust this severe, will most certainly leave behind pitted and damaged surfaces. If I were to simply run the parts through the cleaning machine they would come out clean of oils and dirt, and still rusty.
Just getting the watch apart will be a challenge, because this rust is quite heavy. Most likely all the wheels will need replacing, so balance complete (lucky to find one under $600), escape wheel and pallet fork, which are both not available from Omega also. Then the chronograph parts like the springs etc. would all have to be looked at, and although you might be able to save the odd thing here and there, it won't be much in my view.
When doing a restoration like this, each part has to be looked at to make sure it's sound for it's intended purpose, so for something like a spring or lever, it has to not be weakened to the point it will break or fail to do the job. Then all rust must be removed - rust never sleeps as the saying goes.
Then if the parts has what I refer to as "operating surfaces" they have to be looked at to make sure they are in good shape. So on the hammer for example, where the flat polished surfaces meet the cams on the chronograph runner and minute recorder runner, those have to be flat, not pitted, and polished to a shine. Removing a lot of material to do this can cause problems, so if they are really bad, the piece must be replaced even if the rest looks good.
Donor movement is the way to go on this one.
Cheers, Al
